"It's hard to have a casual conversation in a situation where you have to be paying attention like that," he says.
Current prototypes can be held in the user's hand or worn around the back of the neck, but once the acoustic processing software is developed, it could be easily incorporated into existing smart phones, according to the researchers. To lay the groundwork for such future applications, the researchers are investigating the best way to transform sound waves into vibrations.
Existing tactile aids have been in use for decades, but the MIT team hopes to improve the devices by refining the acoustic signal processing systems to provide tactile cues that are tailored to boost lip-reading performance, says Reed.
As part of their project, the researchers have done several studies on the frequency reception ability of the skin. The human ear can perceive frequencies up to 20,000 hertz, but for touch receptors in the skin, optimal frequencies are below 500 hertz.
Using a laboratory setup with a device that can provide distinct vibration patterns to three fingers simultaneously, Moallem has done preliminary studies of deaf people's ability to interpret the vibrations from tactile devices.
This project was originally inspired by earlier studies Reed did on the Tadoma technique, a communication method taught to deaf-blind people. Practitioners of that method hold their hands to someone's face while they are talking, allowing them to feel the vibrations of the face and neck.
Reed's study, done about 20 years ago, showed that the deaf-blind subjects could successfully understand speech with this method especially if the other person spoke clearly and slowly.
"We were inspired by seeing what deaf-blind people could accomplish just using the sense of touch alone," says Reed.
|Contact: Elizabeth Thomson|
Massachusetts Institute of Technology